Complete elastic characterization of viscoelastic materials by dynamic measurements of the complex bulk and Young's moduli as a function of temperature and hydrostatic pressure

• Published in: Journal of sound and vibration Vol. 330; no. 14; pp. 3334 - 3351
• Main Authors: Guillot, François M., Trivett, D.H.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 04.07.2011; Elsevier
• Subjects: Compressibility; Cross-disciplinary physics: materials science; rheology; Dynamical systems; Dynamics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Hydrostatic pressure; Materials science; Materials testing; Measurement and testing methods; Modulus of elasticity; Physics; Poissons ratio; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Vibration; Viscoelastic materials; Elastic constant; Viscoelasticity; Compressibility; Propagation velocity; Deformation modulus; Temperature effect; Vegetable oil; Vibration test; Experimental study; Young modulus; Dynamic measurement; Poisson ratio; Arbitrary shape body; Castor oil; Hydrostatic pressure; Piezoelectricity; Material testing; Rubber; Bulk modulus; Electromechanical properties
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2011.02.003

Two independent systems to measure the dynamic complex Young's and bulk moduli of viscoelastic materials as a function of temperature and hydrostatic pressure are described. In the Young's modulus system, a bar-shaped sample is adhered to a piezoelectric shaker and mounted vertically inside an air-filled pressure vessel. Data are obtained using both the traditional resonant approach and a wave-speed technique. In the bulk modulus system, the compressibility of a sample of arbitrary shape immersed in Castor oil and placed inside a pressure chamber is measured. Data can be obtained at frequencies typically ranging from 50 Hz to 5 kHz, at temperatures comprised between −2 and 50 °C and under hydrostatic pressures ranging from 0 to 2 MPa (Young's), or 6.5 MPa (bulk). Typical data obtained with both systems are presented, and it is shown how these data can be combined to completely characterize the elasticity of the material under investigation. In particular, they can be used to obtain experimental values of the complex Poisson's ratio, whose accurate measurement is otherwise quite challenging to perform directly. As an example, the magnitude and loss tangent of Poisson's ratio are presented for a nearly incompressible rubber.